1a.Objectives (from AD-416)
1) Develop thermal (50-90 C) and non-thermal (<25 C) extrusion-based processes that alter the structures of whey proteins (texturize), identify the process conditions, and develop models that relate the conditions to the quality attributes of texturized proteins. .2)Create co-products linking the texturized whey proteins with carbohydrate and protein polymers such as soy proteins to make health-enhancing products. Characterize the rheological and viscoelastic properties of the texturized whey protein co-products as specialized ingredients with improved quality and functionality.

1b.Approach (from AD-416)
Changes in texture of whey protein concentrates and isolates, alone or in combination with starches and polysaccharides, will be induced through thermal and non-thermal processing. Thermal and non-thermal extrusion process parameters that affect structure and function relative to texturization of whey proteins will be determined. The properties of the shear-texturized proteins, such as elasticity, gelling strength, expansion, foaming and porosity will be evaluated, along with the rheology and network structure shear-induced viscosity changes that result from changes in protein structure. The thermal and non-thermal texturized proteins will be used alone or to create co-products which will be linked with other polymers such as soy, carbohydrates and other dairy proteins, to create functionalized foods such as low carbohydrate or low-glycemic index snacks, meat extenders and meat analogs.

3.Progress Report
The cooking process affects the crispiness and crunchiness of expanded snack products containing whey proteins. Crispy and crunchy textures in foods have never been clearly defined, and not defining texture of snacks properly, hinders efforts to compare differently processed snacks, or transfer experimental processing technology from the laboratory to industry for production. We researched and worked to provide complete operational definitions of the texture of expanded puffed products using acoustic, mechanical, moisture, and time measurements. The models we have developed so far, compare favorably with those published in the literature, and show that a unifying mathematical descriptor for texture attributes can be obtained. We determined the attributes of crispiness and crunchiness of extruded snacks that are comparable among all processes; these attributes will be needed by the industry in developing healthy foods that consumers will like.

4.Accomplishments
1.
The Perfect Snack with Low Sugar, High-Protein and High-Fiber: Food processors are constantly looking for new ingredients to improve the health benefits provided by their products to consumers. One such new ingredient is pea starch. Pea starch is extracted from green peas through a process that removes the chlorophylls (green color), but retains the protein and fiber. ARS scientists in Wyndmoor, PA working in collaboration with scientists from New Zealand who created the pea starch demonstrated that pea starch combined with whey protein concentrate and oat bran resulted in a crispy crunchy snack. This new healthy snack product will be of interest to healthy food manufacturers.